supercharger or turbo?

[SubieNate]

Here's a question. What kind of cruise economy can we expect from each type of forced induction?

Nathan

[Circuit Motorsports]

This is a Personal Preference item, so there is no right answer.

But there are pros and cons.

If it were my car - I think the Vortech kit is the way to go, reasons:

1. OEM look install
2. Self contained kit, no need for more oil lines, pumps, reservoirs etc.
3. Power delivery, will be like driving a Juiced up NA engine, think stock car on steroids.
4. Simple bolt on kit with mild power upgrade on stock fuel system.
5. Industry tuning and support, stateside support from Vortech

I think the 2 big things people dont realize about the turbo kit is how much heat it will put off and oiling it. Even with coating the header/manifold properly and maybe coating the turbo or using a blanket you are introducing a lot more heat into the engine bay.

You are now also going to be using the oil to cool down and lubricate an extra mechanical item in the engine bay. So you now have a lot more fittings and hoses that need to be checked periodically for leakage. You also have a new item (pump) that could fail. Oil if the lifeblood of your engine, something goes wrong there and you're in trouble. I would not be running that kit without an oil cooler.

Downsides - you do not have the easy power potential of a good turbo setup. you won't have that surge of power like a turbo, and you do get some parasitic loss through the belt. To me those are worth the benefits though.

I am not hating on the turbo kit nor on AVO. I am sure the kit is of good quality and they have said to have done some extensive tests.

This is just my thoughts on the matter

-Tristan

[Tansey86]

Originally Posted by SubieNate

Here's a question. What kind of cruise economy can we expect from each type of forced induction?

Nathan

While cruising you should not see boost from either, thus the only thing I believe will affect your economy is the tune that goes with the new found power adder. Ive actually seen highway/cruise MPG increase with a turbo setup. Then plummet when you put the pedal down

[SubieNate]

Don't SC's make boost all the time?

Nathan

[bobobis]

is there a way to make the avo kit legal in california due to emission laws and stuff?

[JP]

Not everyone is in the US...

[FreshFRS]

Originally Posted by SubieNate

Don't SC's make boost all the time?

Nathan

only when under load. most SC have some way of cutting power to the charger during cruising or low load situations.

[SubieNate]

AFAIK that's only if the pulley is clutched... which none of the available kits have right now.

Nathan

[FreshFRS]

Originally Posted by SubieNate

AFAIK that's only if the pulley is clutched... which none of the available kits have right now.

Nathan

by-pass valves can also allow for the same effect. the Innovate kit will have one of these. an electric solenoid that re-directs air causing the screws to rotate with little to no air thus creating a reduction in drag, allowing only a very small amount of power to be used to turn the supercharger under small loads, this is closed when you punch it. allowing the screws to suck in more air. and thus generate boost. IIRC

[serialk11r]

Bypass valves reduce Roots blower losses to nearly nothing, but twin screw chargers will suck a lot of power even with a bypass and need to be declutched. Centrifugal chargers will suck some amount of power with a bypass too but I think it's not as bad as a twin screw.

[FreshFRS]

Originally Posted by serialk11r

Bypass valves reduce Roots blower losses to nearly nothing, but twin screw chargers will suck a lot of power even with a bypass and need to be declutched. Centrifugal chargers will suck some amount of power with a bypass too but I think it's not as bad as a twin screw.

thanks for the proper explanation sir.

[Calum]

Originally Posted by serialk11r

Bypass valves reduce Roots blower losses to nearly nothing, but twin screw chargers will suck a lot of power even with a bypass and need to be declutched. Centrifugal chargers will suck some amount of power with a bypass too but I think it's not as bad as a twin screw.

This seems to contradict what you're saying. Which do you think would be better, the twin screw or the roots?

http://kennebell.net/KBWebsite/Commo...romcatalog.pdf

[FreshFRS]

Originally Posted by Calum

This seems to contradict what you're saying. Which do you think would be better, the twin screw or the roots?

http://kennebell.net/KBWebsite/Commo...romcatalog.pdf

not at all. twin-screws with bypass valves still have to act like a supercharger even under low load due to the design. roots at low load consume fractions of a HP but this contributes to what the article said about twin screws boosting faster.

on a side note Eatons TVS (roots style with 4 lobes and 170deg of twist on the rotors) is more efficient thermally than the twin screw, and boosts just as fast while still consuming less hp than a traditional roots or a twin-screw over the whole rpm range. and uses again a fraction of a hp under low or no loads.

overall TVS is best but the one we want for this car isn't in production (R1050, Next gen R1100). twin-scew is better than a traditional roots type set-up.

[Captain Insano]

Great thread. I don't think I can afford to do SC or TC anytime soon, but I love that both already have multiple options released or soon to be released. Options are great. I think looking at options right now (things could easily change as aftermarket evolves) I would go with a SC due to it being much simpler design, should make 270-300 reliable crank hp, and I love that the Vortech looks basically OEM like it came from the factory. Totally sleeper and that's great for me. I don't like overly outrageous mods on my car.